The objective is a better understanding of the pathophysiology of stroke. The program features an integration of the research activities of the Departments of Neurology, Neurosurgery, Neuropsychology and Diagnostic Radiology in the study of cerebral vascular disease. The research emphasizes and explores the utility of 31-P Topical Nuclear Magnetic Resonance (TMR) proton spectroscopy and proton NMR imaging in the study of brain anatomy, cerebral blood flow (CBF) and energy phosphate metabolism in clinical patients with stroke. Administrative, statistical and methodological cores and four individual projects are proposed. The methodological cores describe the NMR facility, CBF laboratory and Neuropsychological laboratories. Project 1 proposes early experiments towards the development of NMR methods for the eventual autoradiographic measurement of CBF. The second project explores the dynamic changes in cerebral energy metabolism as measured by 31-P NMR and 1-H in a cat models of global and focal cerebral ischemia. Studies of the clinical patient with stroke begin in Project 3 with a proposal to improve and explore the utility of the 133-Xenon inhalation technique for the measurement of CBF and to establish abnormal CBF as a risk factor for stroke. Project 4 proposes to apply 31-P and 1-H spectroscopy together with NMR imaging to the study of the clinical patient with diffuse hemispheric ischemia and focal ischemic infarction. The eventual goals of this Program Project are to establish noninvasive techniques to identify hemodynamic and metabolic markers which permit the logical and safe therapy of acute and chronic ischemia in cerebrovascular disease by either medical or surgical means.